This invention relates to a tool for removal of an engine cylinder liner and more particularly to a tool for removal of an engine cylinder liner and piston assembly.
A cylinder liner is commonly used to define the combustion chamber of an engine, thereby providing a substantially frictionless mating surface for the piston rings of a piston assembly. The cylinder liners require replacement due to liner wear brought on by the combustion process and the linear reciprocating movement of the piston rings against the interior wall of the liner. When replacing the cylinder liner which is force fitted into the block of the engine, a tool is required to disengage and pull out the worn liner from above the engine. Typically, the piston assembly must first be detached from the crankshaft and pulled out through the top of the cylinder liner prior to removal of the cylinder liner itself Once the piston assembly is out of the way, the tool axially extends through the cylinder liner to grasp the bottom edge. Once grasped, the cylinder liner disengages and is pulled out through the top side of the engine block.
Unfortunately, not all engines have piston assemblies capable of removal prior to removal of the cylinder liner. Sometimes, the piston rod foot, that part which circumferentially surrounds the crankshaft, is wider than the inner diameter of the cylinder liner. In such instances another means most be developed to grip and disengage the cylinder liner for removal, since the un-removed piston assembly blocks access to the bottom edge of the cylinder liner.
The invention provides a tool having a gripping portion for frictionally engaging the inner wall of a cylinder liner. A radially extending stop is located at a leading end of a rod. Trailing the stop is a mandrel having an outer surface for engaging the cylinder liner. The rod longitudinally penetrates the mandrel. Disposed between the stop and the mandrel is a plate radially extending short of the outer surface of the mandrel. Threading to a trailing end of the rod is a nut. Located between the nut and the mandrel is a shoulder having a shelf portion penetrated by the rod. The shelf portion is generally perpendicular to the rod and engages the mandrel.
When the nut rotates down upon the shoulder from a trailing position to a leading position, therein defining an axial engagement range length, the mandrel compresses and extends radially outward, forcibly engaging the cylinder liner. Preferably, the mandrel has a recess concentric to the rod. The recess enhances the compression capability of the mandrel. A plug portion of the shoulder extends into the recess of the mandrel thereby assuring the mandrel distends in a radial outward direction, and not inward. Preferably, the cylinder liner removal tool has a torquing portion for engaging and torquing down upon the nut of the gripping portion. And, the tool has a removable lifting portion for pulling the cylinder liner and the piston assembly from the engine block.
By use of the cylinder liner removal tool of the present invention, a cylinder liner can be removed from an engine block by gripping the internal wall of the cylinder liner. Furthermore, the cylinder liner can be removed complete with the piston assembly.